As a piezoelectric actuator, as shown in FIG. 12, there is known a piezoelectric actuator employing a bimorph-type piezoelectric element 10 which is constructed by forming a surface electrode 104 on the surface of a stacked body 103 composed of internal electrodes 101 and piezoelectric layers 102 which are stacked on each other (refer to Patent Literature 1).
Moreover, there is known a construction in which a flexible substrate is joined to a main surface of a piezoelectric element by an electrically-conductive joining member, so that a surface electrode of the piezoelectric element and a wiring conductor of the flexible substrate can be electrically connected to each other (refer to Patent Literature 2).
Furthermore, there is known a piezoelectric vibration apparatus in which a midportion and one end of a bimorph-type piezoelectric element in the direction of its length are fixed to a vibrating plate (refer to Patent Literatures 3 and 4).